While ultraviolet light can be useful in commercial processing, contact with ultraviolet light has a detrimental effect on biological organisms. Harmful ultraviolet light can come from both sun light and from artificial light sources. The risk from exposure to ultraviolet light from natural sun light is increasing in portions of the world due to occasional significant drops in the UV-absorbing ozone layer. Cost effective ways of reducing human exposure to harmful ultraviolet light are desirable.
On the other hand, some commercial processes use UV light as a processing tool. In order to make effective use of UV light in the processing of microscopic components, precise control of the light absorption is advantageous. In addition, photocatalytic materials can catalyze chemical reactions upon exposure to appropriate light. Efficient approaches for utilization of these commercial processes can greatly expand their commercial scope.